331 Hemi Blown Help

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JeffreysDart

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I have a 331 Hemi and am new to building a Hemi. I plan on doing a rebuild on the core... but do i need Forged Rods and Pistons for a 6-71 Blower with a standard stroke & steel crank? I will most likely run lest than 10lbs of boost. Pump Gar and street 10:1 compression ratio it will be bored .030 over.

any info is appreciated. This will be in a 69 Dart and a street only cruiser car.
 
Early Hemi cranks will stand 1500 + HP. Use good rod bolts and have the rods reconditioned with forged pistons and you won't have any trouble.
 
Do 331's fit a bodies pretty well?
A 331 would be a nice plant in my Cuda!
 
Yeah. There's a member here who has a 354 in a 65 Valiant. I think his screen name is 65Valiant. The car is red.
 
I measured the width on a 330 desoto hemi.
Also measured the width on a 426 hemi.
These are both measured at the widest point outside the valve covers.
Both are 28" across. Stock tin v- covers.
I have no red rams or 331- 392 Chrysler to measure so perhaps someone else can get measurement's for those.
 
for any early HEMI in fo or stock or performance parts look up trwaters.com or hothemiheads.com
 
Does your Dart have stock inner fenderwells? If not, you should consider building a 392. I don't think the 392 would fit in the stock A body engine bay. The 392 has a 0.50" taller deck height than the 331-354 blocks.

I realize you already have a 331, but I'm just wondering if you'd be better off building a 392? The cost of building an early Hemi, to only have 331 cubes doesn't seem worth it. You're already looking at custom headers, and motor mounts. Plus, the early Hemis are no lightweights.
 
The 392 heads are also sucky compared to the big port 331 and 354 heads. You can use the 331 and 354 heads on the 392, if you use an intake that feeds each side like the old Weiand Drag Star or the U Fab.
 
JeffreysDart said:
I have a 331 Hemi and am new to building a Hemi. I plan on doing a rebuild on the core... but do i need Forged Rods and Pistons for a 6-71 Blower with a standard stroke & steel crank? I will most likely run lest than 10lbs of boost. Pump Gar and street 10:1 compression ratio it will be bored .030 over.

any info is appreciated. This will be in a 69 Dart and a street only cruiser car.
Click to expand...


I think the compression would need to be at 8:1 or less to run blower.
 
duster360 said:
I think the compression would need to be at 8:1 or less to run blower.
Click to expand...

No problem there, as the highest compression ever on the 331 was 8.5:1 in 1955 only. Other than that it was either 8:1 or 7.5:1.
 
Its a stock Dart with the inner fender wells..... yes i agree with the 392.... of coarse id love a an all aluminum 572 Hemi... but there is always time and money to upgrade.

Yes that may be the compression... just looking to put a street Hemi together and run the blower.
 
RustyRatRod said:
The 392 heads are also sucky compared to the big port 331 and 354 heads. You can use the 331 and 354 heads on the 392, if you use an intake that feeds each side like the old Weiand Drag Star or the U Fab.
Click to expand...

Definitely correct about the heads, although a blower would overcome some of the intake port deficiencies of the 392 heads.
 
A guy I know built a blown 331 for a front engine dragster. He used custom pistons with aftermarket pontiac rods. He said the length and big end were the same, different piston pin. They were off the shelf rods for a pontiac.
 
I think you'll enjoy your Dart. For a street only cruise car it should have plenty of get up and go and with the blower on the HEMI you'll get plenty of drooling lookers too. I have a 354 HEMI in my '69 Dart and it always gets lots of looks.
 
Ask "Zigs" on here, I think he had a 354. he pulled it out, is putting a 440 in
 
I have a nice factory sealed FEL PRO 1955 Chrysler 331 FULL Gasket Set ......
I presume you are going to require NEW Gaskets -- want to go with what was
the best?!?!?!?!
 
70Swinger440 said:
Does your Dart have stock inner fenderwells? If not, you should consider building a 392. I don't think the 392 would fit in the stock A body engine bay. The 392 has a 0.50" taller deck height than the 331-354 blocks.

I realize you already have a 331, but I'm just wondering if you'd be better off building a 392? The cost of building an early Hemi, to only have 331 cubes doesn't seem worth it. You're already looking at custom headers, and motor mounts. Plus, the early Hemis are no lightweights.
Click to expand...

Sure,he should sell his lighter,shorter,narrower engine w/superior heads to go find and buy
the highly sought after 392 that belongs in a 300 series or Imperial and will certainly make it
easier to fit headers/mannys into an a-body, so as not to be "stuck" w/a supercharged eng.
displacing about 340ci after a .030+forged clearance bore job.Hmmmm....,who else has made
a supercharged smallblock a-body.......I wonder.
Pontiac rods & pistons,really?This is probably the most supercharged,nitromethaned engine
in history,second only to the second gen HEMI, and we're scrounging for pontiac parts?WTF?
 
JeffreysDart said:
I have a 331 Hemi and am new to building a Hemi. I plan on doing a rebuild on the core... but do i need Forged Rods and Pistons for a 6-71 Blower with a standard stroke & steel crank? I will most likely run lest than 10lbs of boost. Pump Gar and street 10:1 compression ratio it will be bored .030 over.

any info is appreciated. This will be in a 69 Dart and a street only cruiser car.
Click to expand...

Herb Adams,Hot Heads ,this is all He does practically, look him up and call.Rusty said
it,these things can take a pounding,top of the line rod bolts are plenty for any modest boost.
 
Bob Walker, TR Waters, Chuck Taylor.....all huge names in the early Hemi world and can and will give you great advice........although Chuck Taylor is really getting up there. He's a legend no doubt.
 
Also try to hook up with "Early hemi Bill" He was on here building a really cool TT injected hemi Valiant. I don't know if he's had health issues, or what

[ame="https://www.youtube.com/watch?v=bPrnlUsxls4"]Bill's Desoto 341 hemi part 5 - YouTube[/ame]

http://www.forabodiesonly.com/mopar/showthread.php?t=240702

attachment.php


http://www.jalopyjournal.com/forum/media/albums/injected-341-desoto-hemi.7689/

1743936-5d9f80a383ef01b54460e406bf9d8a60.jpg
 
Killer6 said:
Sure,he should sell his lighter,shorter,narrower engine w/superior heads to go find and buy
the highly sought after 392 that belongs in a 300 series or Imperial and will certainly make it
easier to fit headers/mannys into an a-body, so as not to be "stuck" w/a supercharged eng.
displacing about 340ci after a .030+forged clearance bore job.Hmmmm....,who else has made
a supercharged smallblock a-body.......I wonder.
Pontiac rods & pistons,really?This is probably the most supercharged,nitromethaned engine
in history,second only to the second gen HEMI, and we're scrounging for pontiac parts?WTF?
Click to expand...

First of all, it was a suggestion, people can have an opinion. Second of all, you can use the 331 and 354 heads on the 392, making that a moot point. Third of all, where did I say anything about being stuck with anything, and where did I say he shouldn't use the supercharger? Fourth of all, what's the problem with using aftermarket internal parts made for other make engines?
 
No kiddin. I like different opinions. Might gimmie a idea I ain't had before. ....and certainly notta thing wrong with more kyoobs, BUT this IS a early Chrysler Hemi we're discussin and people don't just GIVE those away. lol
 
At 8.5:1 static compression you'll want to limit boost to around 6 lbs to run on pump gas with a roots blower. At 7:1 you could push 10-12 lbs. Wound up, that'll theoretically put you in the 12: x compression range. You'll make tons of grin-inducing, tire-smoking power on the street.

I've got an early 331 I'm going to pull out and play with one of these days.
 
RustyRatRod said:
No kiddin. I like different opinions. Might gimmie a idea I ain't had before. ....and certainly notta thing wrong with more kyoobs, BUT this IS a early Chrysler Hemi we're discussin and people don't just GIVE those away. lol
Click to expand...

Agreed about the price to play in early Hemis. I'm sitting on a decent pile of engines and parts, bought before the nostalgia craze really took off. I can't believe what some of this stuff sells for now.
 
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